Where is all this drool coming from??

I've never drooled in my life. Ever. Yet in the past week or so every single day I wake up in a tiny pool of my own making. Where does it come from? I haven't noticed that I have more saliva than usual...and I do normally sleep with my mouth open so what's going on?

Oh man I went through a stage of having to spit into a cup every few minutes because I was swallowing so much saliva it was hurting my stomach. I really felt the joys of pregnancy at that point. I still dribble in my sleep and have even taken to waking myself up with a huge pig like snort several times a night due to weight gain. I am gorgeous.